Shell Rot
by Stupid computer
Summary: If his brothers saw the burns and scars that peppered his hands they would be worried, maybe even scared. So the lab was kept restricted for most of the time and Donnie made sure to wrap his injuries before anyone could see them. However, burns and scrapes were not his biggest problem. *I wrote this really quickly so it's a piece of trash. I am sorry*
1. Chapter 1

**This is trash, don't read this. I've just had this idea in my head for a while now and...just don't read it. I might revise it later and make it actually good but for now...sorry. **

Working with mutagen was a dangerous task, one wrong move and there would be nothing but chaos. While trying to create a retro-mutagen Donnie had taken all necessary precautions and then some. But accidents happened. Mutagen was a highly unstable substance; there were explosions and spills and unbalanced formulas. Despite all of this, Donnie never sustained anything more than a bad burn every now and then. None of his brothers ever came into the lab for extended amounts of time so they were never there for any of the big mishaps. Donnie was glad for this fact. If his brothers saw the burns and scars that peppered his hands they would be worried, maybe even scared. So the lab was kept restricted for most of the time and Donnie made sure to wrap his injuries before anyone could see them. However, burns and scrapes were not his biggest problem.

It was few days after Donatello had discovered the retro-mutagen and had helped turn April's father human once more when things started to go bad. One night without warning, Donnie closed off the lab; sealed it up tight in a frenzy of wielding tools and fire. That night had been particularly bad for everyone.

* * *

Mikey had been the first to hear the noise, a deep distant echo that bounced around his head. He opened his eyes slowly. He wasn't quite ready to relinquish his last few hours of sleep to the noise. After several minutes of the noise it was clear that it wasn't going away. He huffed sadly as he shed his blankets to meet the cold, night time sewer air. It came to no surprise to see Raph and Leo up when Mikey made his way to the hallway.

"What the heck is goin' on?" Raph asked, the usual venom of his voice being replaced by a suppressed yawn.

"It sounds like it's coming from Donnie's lab." Leo replied in the same sleepy tone.

The three brothers groggily made their way to the lab where they found Donnie, wielding torch in hand, sealing the large hanger doors that opened out into the subway shut. There was sweat dripping down his face and his movements were jerky and rushed. The wielding job looked like a mess, chard marks were everywhere, and even the floor was not safe from the crackling flames.

"Donnie? What are you doin'? It's one o'clock in the morning."

Donnie jumped at Raph's voice, making another stray mark on the doors. Frantically, he turned the torch off. He reached to his eyes as if to take of his usual wielding goggles but they weren't there. The same thing happened when he tried to take of his usual wielding gloves. He had forgotten to wear any safety equipment, something highly unusual for him.

"G-guys! Whatryou doing here? I wasjust, just doing some stuff. Juststuff. Somestuff." Donatello's words were choppy, running together in a frenzy. One of his eyes had a slight twitch to it.

"Have you been up all night Donnie?" Leo reached forward to his brother but Donnie jumped out of his reach.

"No. Yes. Maybe? What timesit? Did I wake you? Sorry, 'mreally sorry. Ok, I'll be quiet. You guys should 'eave now. Leave now."

Now Leo was defiantly concerned. Donnie wasn't acting like himself at all. He usually got a little wound up when he stayed up to late but there was something more going on. Donnie kept twitching and his eyes were dilated. He wasn't acting mad at them for being in his lab without permission nor was he irritated at them for disrupting his work. If anything he looked scared.

"You alright D? You look a little pale." Mikey tried to brush his hand against Donnie's forehead to see if he had a temperature. In turn Donnie smacked his hand away.

"Don't touch me! Do. Not. Touch. Me!" He screamed out.

"Gesh Don, what's your damage tonight?" Raph made a third attempt at grabbing his brother.

"I said don't touch me! Now get out! Get out, get out, get the hell out of my lab!"

That was the last thing said before Donnie roughly bushed all of them through the lab's front doors.

"What the shell just happened?" Raph asked in confusion.

Mikey and Leo exchanged hurt, questioning glances.

"I don't know. As leader I think it's best if we go back to sleep and let Donnie have some alone time. We'll talk about it later."

Later never came. By the time the brothers started morning training the lab had been completely wielded shut.

* * *

After that Donnie refused to leave his room except to eat or get water. He skipped practice which worried Master Splinter more than it angered him. Everyone tried to coax the purple banded turtle out; Mikey asked him to play board games, Raph threatened him, Leo tried to get him to play video games, April asked him if he wanted to watch some movies or hang out, and even Casey tried to rile him up enough to come out. But nothing worked.

Soon Donnie stopped coming out for food. This was especially disheartening. Everyone would take turns bringing him food and trying to talk him into coming out. Every time they would just end up putting the plate down outside his room and coming back to find that it had been barely touched. The cycle continued for several days until one day when everyone was in the living room watching cartoons and trying not to think about what was wrong with the technologically inclined turtle. They were halfway done with watching a re-run of Space Heroes when there was a soft shuffling sound. Standing by the dojo was Donnie; or at least there was no one else he could be.

His usual olive coloured skin tone had turned into a sickly pea green, everything about him seemed smaller and thinner, and his shell was bumpy and flaky. Pale scars ran down his plastron, on one side it looked like an entire piece had been picked off.

"There's something I need to tell you guys." Donnie's voice was raspy; the area around his mouth was dry as a bone despite the thin line of drool falling down his chin.

Everyone in the room was in shock over Donnie's state. April was the first to take action.

"Oh my god, Donnie what happened to you?" She ran over and helped Donnie down onto the couch beside Mikey.

Leo and Raph ran off quickly to get Master Splinter and arrived a few seconds later with their father by their sides. They still hadn't said anything, too shocked by their brother's appearance. Once Master Splinter saw his son, he rushed over to his side.

"Donatello, my son, how did this happen?" Master Splinter's eyes darted up and down his son's figure, taking in all the damage that had been done to it. There was silence in the room as everyone held their breath. Donnie let out a sharp cough before speaking.

"The mutagen, I'm sorry I should have told you all sooner. I was scared. When I figured it out I was so scared for myself and everyone else. I'm sorry, I should have told you."

"What about the mutagen Donnie? What happened?" Leo was knocked out of he shocked trance and went to wrap an arm around his brother. The action cause Donnie to flinch but he did not pull away.

"Mutagen, while not stable, is usually safe to be around as long as you don't come in direct contact with it. But it was still a chemical. I should have been smarter, I should have known but I-I didn't. I'm s-sorry. I'm s-so s-sorry."

"Hush Donatello, it is alright. Please my son, tell us what is wrong."

Donnie stared at the floor, his eyes absent and misted over with film. He didn't cough again but he did make a noise in the back of his throat.

"My tests. I tried to be careful, I did everything I should have done to contain the substance on a physical level but it wasn't enough. I didn't realize it at the time but during one of my tests something happened. I didn't realize it until now but-but some the substance turned…radioactive. The lab walls contain it but…but I spent too much time there. I started feeling weird a few days after April's dad got back so I did a test on myself. The radioactive mutagen reacted with the mutagen I have in my blood stream and now…" Donatello broke off and started coughing violently into his hand.

"That's why you closed up the lab." Raph said with sudden realization.

"Mhm." Donnie absentmindedly scratched at his plastron causing little flakes to fall onto the ground. "Shell rot." He said once he saw everyone looking at him.

"Do you think, Donnie, do you think you'll be able to cure it? Donnie?"

Donnie didn't respond to Mikey's question.


	2. Chapter 2

**Apparently my story wasn't a piece of thrash so here's a second chapter for all you nice people who reviewed. **

***This chapter has a lot of swearing!***

Donatello got worse with each passing day. His skin changed from pea green to a pale cabbage colour. Angry red sores broke out against his thinly stretched flesh, pulsing with swollen blood vessels and a yellow crust around their bases. A few of them had popped, splattering nearby objects with thick, runny balls of bright puss. The puss would pool around Donnie's skin, sometimes filling the already opened crevices of blisters and sores that had recently exploded and festering within them. The pain from this was excruciating at first. Donnie would howl out as loud as his dry throat would let him whenever a new sore would open, spilling its sticky contents out onto him. Someone would always come to his aid when this happened. They would try their hardest to clean the new wound but doing so hurt Donnie more than the actual popped blister. Most of the puss was left to simmer against his papery skin and drip down his face. These sores weren't even the worst part.

Donnie's shell was rotting away at an alarming rate. What started out as just a few flaky spots turned into long lines of deteriorating cartilage. Being a mutant, Donnie and his brothers didn't have normal turtle anatomies. Their ribs and spines did not connect with their shells. Instead they were connected by a layer of skin. In some places Donnie's plastron had rotted to the point where this thin layer could be seen. It held a slimy sheen and was raw from the exposure to the open air. The layer of skin gave off the smell of old meat that had been left out in the sun. The scent made Donnie's eyes constantly water. His tears then mingled with the bloody scratch marks along his cheeks from where he had desperately clawed at his boils.

His only saving grace was the fact that his family refused to leave his side. Though he was confined to his bedroom he was never without company. Leonardo, with the help of Raphael, had moved the T.V into Donnie's room so they could still watch shows together. Leo always let Donnie pick what they watched and never complained about what he chose. Michelangelo spent every moment not training or eating in Donnie's room. Sometimes he even had to be dragged out so his brother could get some rest. Mikey had changed the most due to his brother's illness. He no longer joked or laughed unless it was for the benefit of Donnie and even there was no real enjoyment behind his giggles. Raph also had a rough time coming to terms with his brother's condition. His visits to Donnie were short and few. Afterward he would storm his way to the dojo and practice until his fists were bruised and at least one training dummy was broken.

To make up for Raph's absence, April spent more time with Donnie. She would sit with him and quiz him with problems from her text books. Donnie enjoyed having the simple questions as a distraction from his physical state; his body might have been deteriorating but his mind was still as sharp as a tack and that gave him an odd sort of comfort. However, the more time he spent with April, the sourer his regard for her became. He wasn't stupid, he knew that her sudden intense interest in him was merely an act of situational pity. Somewhere in his mind he knew that a bit of pity in this type of situation couldn't be helped but he still didn't like it.

He snapped at her more often and made more snarky remarks. She never argued back though. Donnie would never yell or insult April outside of a few short, bitter comments but he knew that even if he did she would just sit there and take it. Sometimes when he said something offhandedly rude she would give him a sad smile, close whatever book she had been reading from, kiss him on the forehead, and leave. Donnie considered the kisses the worst part. April seemed to give them out to him more freely once he had revealed how sick he was. What was once a sweet gesture to be savored soon became routine and meaningless. An act of 'you're sick so I'll do this for you as a favor.' That wasn't what Donnie wanted. He never wanted to force her into affection.

Soon it wasn't just April who gave him those looks of pity which turned his stomach and head sour. His brothers started treating him differently as well. When they looked at him it made him feel as though he were no longer their equal. He was just a poor, pitiable child. The part that upset Donnie the most was that-despite how he wished to be viewed-they were right. He was ill and pathetic and bed ridden and it was as if his family would take every means to remind him that he was such. Some nights when Donnie pretend to be sleeping he would hear Master Splinter come into his room. He would come to cry over the son who was dead while his heart still pounded. Splinter would morn his death before it truly came. And that action alone broke every bit of Donnie's heart. No longer was he viewed as a person, he was rather a death waiting to happen.

The one exception to this view came in the form of Casey Jones. Casey would skin a class or two most days to hang out with Donnie but besides that nothing outwardly changed between them. Casey might have softened up a bit and sometime he was caught giving Donnie a glance of pity but Casey tried to be the same. He would taunt and tease Donnie, touch all his stuff without permission, talk about hockey, and kept track of what he had dubbed the kiss-count-challenge. The kiss-count-challenge wasn't really fair anymore seeing how April would give Donnie a kiss each day when she saw him but there was still a small ounce of pride when he found out that the score board sat at 19 to 0.

"It's only because you're sick. Trust me, once you get better my chances are going to be through the roof. You can still be a pretty bridesmaid at our wedding if ya' want."

Donnie gave Casey a halfhearted shove, the words 'once you get better' ringing dully in his head.

* * *

The night everyone realized it would soon be over was the night Donatello coughed up blood. Mikey had been with him telling him about the plot of a comic-Donnie's special request-when it happened. The cough had started as a gurgling sensation in Donnie's stomach like the build up to a belch. Then without warning his lungs caught fire with pain. They constricted tightly leaving Donnie gasping for air. When he was able to breathe again he went into a violent coughing tirade. Each jolt of his chest sent a shiver throughout his entire being. Mikey started screaming for Leo and Master Splinter. Donnie was about to calm him down when he caught a glance at his hand. A rich red ran down his palm. It was goopy like long strands of glue and seemed to be a shade darker than normal blood but there was no denying that it was blood.

Master Splinter came rushing in, followed by Leo, Raph, April, and Casey. Master Splinter rushed to his son's side. Mikey moved respectfully out of the way and turned into Leo's chest to let out a scared sob.

"Donatello? Donatello, please my son, can you speak?" Splinter rubbed soothing circles on the parts of Donnie's back that weren't rotted sores.

"I'm-huak-fine Sens-kuhkuh-ei. Hum, ehem, ehem." Donnie cleared his throat carefully. He could feel the strings of blood that hadn't come up slide down into his stomach. The sudden heat flushed his belly.

"Are you sure you're ok Donnie?" Raph asked.

"Y-yeah. I'm fine just-just scared the shit out of me, that's all. Wait, I'm sorry Sensei, I didn't mean to say that!"

Donnie waited for his father to scold him for cursing. He waited. And waited. And waited. The stern words never came. All that Donnie got was a look of sorrow on his father's face. Sorrow, sadness, pity, weariness. It was look that finally broke whatever resolve Donnie had to be at least a little understanding, at least a little compassionate to how he was affecting the rest of his family. Everyone had been walking on eggshells, careful not to mention death or bring light to the fact that someone they loved was dying. The straw not only broke the camel's back, it completely crushed it. Donnie threw his head back and gave out a loud laugh.

"Oh right, I forgot, you're not going to yell at me. I'm-what do you guys say I am? Oh right, I'm _sick. _Because sickness can be cured right? I mean, as long as you don't _call _it dying then the problem will just go away. Well you know what? This. Fucking. Sucks. And I can say that right? I can say that because I'm _ill. _I'm _sick. _I'm just a little down with a _condition_ right? Well fuck fuckity fuck fuck fuck to that biggest pile of shit that I ever heard!"

"Donnie-"Leo spoke in a sensitive tone, not a warning one which only made Donnie madder.

"Don't 'Donnie' me like that. Just don't. You know what? You're leading skills suck ass sometimes. You get so caught up in doing the job the right way that you never think about doing the job the best way! I mean, gees, can you get your head out of your own ass for five goddamn minutes to see that someone else just might have a better plan then you do? And Raph!" Donnie turned his attention to his red band brother who was standing in shock with everyone else.

"Please Donnie, you should go to slee-"More sensitive tones. Raph was adding to the fire of pity and Donnie was not taking it.

"No. No, shut up ok? You, my dear beloved brother, are a dick. Sometimes I forget that you're a person and not a piece of temperamental shit. Not just any piece of temperamental shit, you have the personality of a Mobius strip of crap. A fecal singularity that spans the entire gastro intestinal system! You hide behind your macho persona all the time. And it's so. Damn. Transparent.

"Mikey! Would it kill you to pay attention to someone for five god damn minutes? Casey, I think you're a piece of shit and a giant douche but you already knew that. April…April O'Neil I am so completely and totally in love with you. And I know you know and I wish that you would tell me you don't feel the same way so you can get with Casey because even if I think he's a giant douche the fact still remains that he's a giant douche with a heart of fucking gold. But you won't get with him, will you? Because getting with him means that you turned down a guy who's dyi-oh I'm sorry. Getting with him means that you turned down a guy who's _sick _and heaven forbid you actually go on with your life without feeling guilty for something you had no control over!

"And Sensei…father. Please…please just stop crying? I-I just can't take it. I don't need to be reminded every single day ok? I don't need a reminder to know that everyone here is already picking out a tombstone for me. It's like…it's like you all keep denying what's right in front of you. I'm about to take a dirt nap. The big sleep, buying the barn, punching the ticket, about to take the one way train. You're all spending so much time trying to convince yourselves that I'm not that you're all taking away the last days I have left. You're trying to burn me into your memory but I don't want to be remembered like this! I-I don't w-want your la-last memories of me be-being me yelling at you like a-a superior a-asshole."

Donatello started crying. Fat tears rolled down his face and sat in the deep curve of his collar bone, which became significantly shallower when he stopped eating properly.

"I-I must be th-the biggest fucking fool i-in this room. Because I-I did this t-to myself. It's a-all my fault! There's no cure for radiation poisoning. I wa-wasn't careful e-enough and now…now everyone's going t-to pay for my mistake. Because I'm. Fucking. Dying."

There was a pause in the air while Donnie cried. Everyone had moved closer to him with various levels of tears in their eyes. Mikey was the first to wrap his arms around Donnie and openly speak.

"I'm going to miss you. I'm going to miss you so much when you're gone. I don't want you to die."

"I don't want to die."

Soon everyone was hugging Donnie. April was holding his hand, Casey was gripping at his shoulder, Raph and Leo were both awkwardly gripping his lower chest area, Mikey was resting his head on the crook of his neck, and Splinter rested a hand on his head. Splinter's furry hands grasped at the back of his son's skull. He was trying to wind his fingers through his son's soft bandana tails only to realize too late that the bandana wasn't there anymore.

"Leo?" Donnie was no longer crying when he called for his brother. Leo moved from his spot to look at Donnie. The others soon followed.

"Yeah Donnie?"

"I copied a formula for the retro-mutagen. It's in a notebook under my bed. When you get more mutagen…if I don't make it long enough to make more promise me you will ok?"

"Of course Donnie."

"Bring back Spike and Doctor Rockwell and Spy Roach and Timothy. Especially Timothy. Tell him I'm sorry."

"I will Donnie."

"Train him for me? He won't last a day on his own."

"I'll try. I don't think I have your level of patience for that but I'll try." Leo let out a chuckle as he wiped his eyes. Donnie turned his attention to Casey.

"In that notebook I have some plans for stuff I was hoping to build. As much as it pains me to say it, I think out of everyone you and Raph would be the ones to figure out how they work. There's one specific invention that I want you to make first. I call him Metal Head Mark II. Metal Jr. for short. Think you can handle that?"

Raph and Casey remained silent but smiling, nodding their heads in agreement.

"Donnie?" April looked up from drying her bloodshot eyes and stared intently at her friend. Donnie meet her gaze smiling.

"Yes April?"

"I love you, I'm just not in love with you."

"And thank goodness for that."

April giggled and hugged Donnie again, tighter this time. Everyone started talking after that. Not about anything in particular. Just idle small talk about funny moments from the past. Raph and Casey started scanning over the design for Metal Jr. Casey made a few rude comments about the colour scheme and Raph thought that they should add flames to the paint job. April and Leo talked about making more retro-mutagen to cure the other mutants. By Donnie's side sat the only two people he hadn't addressed directly. His little brother and his sensei. They didn't say anything but that was ok. Nothing needed to be said between them. The youngest and the oldest in Donatello's life knew that he had nothing to say to them besides an understood 'I love you.'

* * *

Four days later Donatello Hamato died and life went on.


End file.
